Alexander h



(No Model.) A E LIMONT.

' f TUBING. No. 408,728. Patented Aug. 13, 1889.

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UNITED STATES PATENT OFFICE.

ALEXANDER H. LIMONT, OF WATERISURY, CONNECTICUT, ASSIGNOR TO A HOLMES, BOOTH & HAYDENS, OF NEW YORK, N. Y.

TUBING.

SPECIFICATION forming part of Letters Patent No. 408,728, dated August 13, 1889.

Application filed December 24, 1888. Serial No. 294,474. (No model.)

To all whoml it may concern.-

Be it known that I, ALEXANDER H. LIMONT, of Waterbury, in the county of New Haven and State of Connecticut, have invented a certain new and useful Improvement in Tubing, of which the following is a specification.

My improvement relates to tubing of that kind which is especially intended for illuminating-fixtures provided with gas-burners and electric lamps. Such tubing consists of an inner duct and an outer duct.

I will describe tubing embodying my present improvement, and then point out the novel features in a claim.

Figure l is aside view of tubing embodying my improvement. Fig. 2 is an end view thereof. Fig. 3 is an end view of a sheet or strip of metal, such as is used for manufacturing tubing of the kind shown in Figs. 1 and 2, and representing said sheet or strip as it appears at one stage in the manufacture of this tubing. Fig. 4 is an end view of this sheet or strip of metal bent to complete the tubing. The edges are not, however, represented as united in this figure, Fig. 2 being a corresponding view illustrating the tubing as completed. Fig. 5 is a view corresponding to Fig. 4. In this view the outer duct is, however, made rectangular in the cross-section instead of circular in the cross-section, as it is represented in Fig. 4. Fig. 6 is a side view of tubing of a slightly-modified form embodying my present improvement. Fig. 7 is an end view thereof. Fig. 8 is an end view of the sheet or strip of metal as'it appears at one stage in the manufacture of this form of tubing. Fig. 9 is an end view of the sheet or strip as finally bent into shape.

Similar letters of reference designate corresponding parts in all the iigures.

Considering irst the example of tubing illustrated by Figs. l, 2, 3, 4, and 5, A designates a sheet or strip of metal which has parallel sides. It is first so bent that its middle portion a will assume the form of a semicircle, so that the imm ediately-adjacent portions a will be tangential to the semicircular portion and parallel with each other, and so that the edge portions a2 will extend on curves outwardly and then parallel with the portions a', as may be readily understood by reference to Fig. 3. Subsequently the straight portions a will be bent to complete the circle, of which the portion@ forms part, and the straight portions a2 will be bent to form a larger circle. These two circles may be seen completed in Fig. 4. The inner one A is, it will be seen, eccentric to the larger and outer one A2. It will be observed that in this example of my improvement the inner circle or duct A is at one portion close to the inner surface of the larger and outer one A2.

The bending may be done by any suitable tools or machinery. As these form no part of my improvement, I will not make further allusion tothem.

The opposite edges a3 of the two ducts, where these ducts are contiguous, are united, and the side edges a4 of the sheet or strip are united. This may be done by brazin g or soldering.

.The tubing provided with the two'ducts A A2 will then be completed in the form illustrated by Fig. 2.

In Fig. 5 I have shown a form of tubing in which the sheet or strip has the parallel portion a bent to complete the circle of which the portion ais a part, and afterward has the side portion a2 bent into the form of a rectangular tube. After this bending the opposite edges a4 will be united, as before explained in connection with Fig. 4.

Obviously the inner duct A may, if desired, be made of angular form in carrying out my improvement.

Turning now to Figs. 6, 7, 8, and 9, it will be seen that the sheet or strip is at the middle bent to form a circle or duct A This may be best understood by reference to Fig. 8. Then the portions a3 of the sheet or strip immediately adjacent to the meeting edges of this circle or duct A are extended parallel to each other and radially to the said circle or duct a short distance. The side portions a2 of the sheet or strip are then bent into circular form and form the outer duct A2, as may be understood by reference to Fig. 9. In this example it will be seen that the two ducts are concentric. The portions of the sheet or strip extending radially from the inner duct A -are united, and the side edges a4 are united by brazng or soldering. The appearance of the Tubing having` two ducts, one within the finished tubing may best be understood by other, and made from one sheet or strip of reference to Fig. 7. metal, substantially as specified.

Tubing embodying my improvement has 5 two distinct and separate ducts. Each may ALEXANDER H. LIMONT.

be used for a different purpose. For example, electric-light Wires may be passed through Witnessesz one and gas through the other. GEO. H. BUCHAM,

That I oiaini as my invention, and desire F. L. ADAMS.

i0 to secure by Letters Patent, is 

